title: Corticosterone induced morphological changes of hippocampal and amygdaloid cell lines are dependent on 5-HT7 receptor related signal pathway.
abstract: Stress is an unavoidable life experience. It induces mood, cognitive dysfunction and plasticity changes in chronically stressed individuals. Among the various brain regions that have been studied, the hippocampus and amygdala have been observed to have different roles in controlling the limbic-hypothalamic-pituitary-adrenal axis (limbic-HPA axis). This study investigated how the stress hormone corticosterone (CORT) affects neuronal cells. The first aim is to test whether administration of CORT to hippocampal and amygdaloid cell lines induces different changes in the 5-HT receptor subtypes. The second goal is to determine whether stress induced morphological changes in these two cell lines were involved in the 5-HT receptor subtypes expression. We now show that 5-HT(7) receptor mRNA levels were significantly upregulated in HT-22 cells, but downregulated in AR-5 cells by exposure to a physiologically relevant level of CORT (50 μM) for 24 h, which was later confirmed by primary hippocampal and amygdaloid neuron cultures. Additionally, pretreatment of cells with 5-HT(7) antagonist SB-269970 or agonist LP-44 reversed CORT induced cell lesion in a dose-dependent manner. Moreover, CORT induced different changes in neurite length, number of neurites and soma size in HT-22 and AR-5 cells were also reversed by pretreatment with either SB-269970 or LP-44. The different effects of 5-HT(7) receptors on cell lines were observed in two members of the Rho family small GTPase expression: the Cdc-42 and RhoA. These observed results support the hypothesis that 5-HT may differentially modulate neuronal morphology in the hippocampus and amygdala depending on the expression levels of the 5-HT receptor subtypes during stress hormone insults.
authors.affiliation: Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL 32611, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Xu
authors.forename: C
authors.initials: C
authors.lastname: Zhang
authors.forename: R
authors.initials: R
authors.lastname: Wang
authors.forename: S S
authors.initials: SS
authors.lastname: Govindarajan
authors.forename: P A
authors.initials: PA
authors.lastname: Barish
authors.forename: M M
authors.initials: MM
authors.lastname: Vernon
authors.forename: C
authors.initials: C
authors.lastname: Fu
authors.forename: A P
authors.initials: AP
authors.lastname: Acharya
authors.forename: L
authors.initials: L
authors.lastname: Chen
authors.forename: E
authors.initials: E
authors.lastname: Boykin
authors.forename: J
authors.initials: J
authors.lastname: Yu
authors.forename: J
authors.initials: J
authors.lastname: Pan
authors.forename: J M
authors.initials: JM
authors.lastname: O'Donnell
authors.forename: W O
authors.initials: WO
authors.lastname: Ogle
mesh_terms: D000679:Amygdala / Q000187:drug effects* / Q000473:pathology; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology; D002460:Cell Line; D003345:Corticosterone / Q000378:metabolism / Q000633:toxicity*; D005260:Female; D006624:Hippocampus / Q000187:drug effects* / Q000473:pathology; D008297:Male; D051379:Mice; D009474:Neurons / Q000187:drug effects* / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D011985:Receptors, Serotonin / Q000235:genetics / Q000502:physiology*; D015398:Signal Transduction / Q000187:drug effects* / Q000502:physiology
chemical_list: D000893:Anti-Inflammatory Agents; D011985:Receptors, Serotonin; C104425:serotonin 7 receptor; D003345:Corticosterone